第30卷第4期2011年7月岩石矿物学杂志ACTAPETROLOGICAETMINERALOGICAVol.30,No.4:665~673July,2011珠江口盆地惠州凹陷深部储层成岩作用与孔隙演化龙更生1,施和生1,郑荣才2,杜家元1,刘军1,张晓宇1(1.中海油深圳分公司,广东广州510240;2.成都理工大学,四川成都610059摘要:惠州凹陷是珠江口盆地重要的油气富集区,但深层古近系的勘探尚未突破,主要是束缚勘探的储层问题没有得到解决。对于深部储层而言,孔隙的发育状况与储层的岩石成分、结构密切相关,成岩作用及孔隙演化对储层的储集性能有重要的影响。本文在对大量薄片和岩芯进行分析的基础上,运用扫描电镜、X射线分析、有机酸测试等手段,对惠州凹陷深层砂岩储层的成岩作用和孔隙演化进行了详细研究。结果表明,压实作用、胶结作用等使砂岩孔隙度降低,不稳定矿物和部分填隙物的溶蚀作用导致孔隙度增大。各井数据揭示珠海组及恩平组深层储集砂岩的成岩强度大部分达到了中成岩阶段B期,有机酸被释放出来,参与溶解作用,次生溶蚀孔隙的大量形成,改善了深部储层的物性,增添了深层的勘探潜力。关键词:惠州凹陷;古近系;储层;成岩作用;次生孔隙中图分类号:P618.130.2+1文献标识码:A文章编号:10006524(201104066509DiagenesisandporosityevolutionofdeepreservoirsinHuizhoudepression,PearlRiverMouthbasinLONGGengsheng1,SHIHesheng1,ZHENGRongcai2,DUJiayuan1,LIUJun1andZHANGXiaoyu1(1.ShenzhenBranchofCNOOCCo.,Ltd.,Guangzhou510240,China;2.ChengduUniversityofTechnology,Chengdu610059,ChinaAbstract:HuizhoudepressionisoneofthemostprolifichydrocarbonareasinPearlRiverMouthbasin.PlentifulNeogeneoilandgashavebeenfound,butnobreakthroughhasbeenmadeinPaleogenesediments.ReservoirporosityandpermeabilityarethoughtverylowinPaleogene,andthisinhibitstheexplorationprogress.Astothedeepreservoir,thefactorofporosityisinconnectionwithpetrographiccompositionandarchitecture.Theskeletoncomponentsandmatrixcomponentsofthesandstonearebasicsubstancesparticipatingindiagenesis.Feldsparsandstone,feldspathicquartzsandstoneandlithicarkosearemainrocktypesinZhuhaiandEnpingFormations,whicharecharacterizedbycoarsegrains,poorgrading,subangularity,lowcompositionalmaturity,andmoderatetobadtexturalmaturity.Thestoragecapabilityisconsiderablyimpactedbydiagenesisandporosityevolution.Basedonslicesobservationandcoresanalysisandusingsuchmeansasscanningelectronmicroscope(SEM,Xdiffraction,cathodoluminescenceandorganicacidtest,theauthorsstudieddiagenesisandporosityevolution.Theresultsshowthatthesandstoneporosityisdecreasedmainlybycompactionandcementationandsubordinatelybyquartzovergrowthandauthigenicmineralfilling.Abundantsecondaryporesareproducedbythedenudationofsuchunstablecomponentsasfeldspar,matrixandcuttings,andthisleadstotheincreaseofthepercentageofvoids.Researchesrevealthatthedeepreservoirhasexperiencedfourdiagenesisevolutionphases,i.e.,syngeneticstage,eogeneticstage(composedofAstageandBstage,anadiageneticstage(comprizingAstage收稿日期:20101025;修订日期:20110517基金项目:国家十一五重大科技专项大型油气田及煤层气开发资助项目(2008ZX05023002(,,,,,Email:com.cn。&Bstageandlatediageneticstage.Welldatashowthatmostofthereservoirshaveattainedtheeogeneticstage,whereassegmentalsandstone(under4000mhasenteredintothelatediageneticstage.Primaryporositywasdecreasedquicklybycompactionattheeogeneticstage(ABbecauseoftheincreasingoverlyingload.LinearcontactoccurredattheBeogeneticstage.Hydrothermalfluidoforganicacidwasdischargedtofastigiumwithmostkerogenbeingtransformedintohydrocarbonattheanadiageneticstage(AB.Duetoincreasingacidity,theunstablecomponentsofaluminosilicateframeworkingredientssuchasfeldsp...